Traditional graphite-plate fuel cell stacks have low power density and high manufacturing costs, which cannot meet the needs of passenger cars. Xell® modules use metal separators. Compared with graphite plates, they have higher electrical and thermal conductivity, lower air permeability, higher mechanical strength, and are easy to mass-produce. Even if the metal separator may be corroded, it can be protected by surface modification. The general stack design often combines the anode separator and the cathode separator into a single component, called a bipolar plate, which has channels for the flow of hydrogen, air and coolant at the same time, so it is also called a flow field plate.
| Item | Metal Seperator | Graphite Seperator |
|---|---|---|
| Material | Stainless steel/titanium | Graphitic powder + thermosetting resin |
| Forming | Stamping/hydraulic forming | Injection/casting |
| Advantage | Easy for mass production Low material cost High electrical conductivity High stack power density |
High anti-corrosion ability High flexibility in geometric design |
| Weakness | Low anti-corrosion ability (need surface modification) Material forming limitation Complex engineering design |
High material cost Long resin curing Low electrical conductivity Low stack power density |
